GENEVA, Switzerland -- Countries are ignoring advice by the World Health Organization in Geneva to mitigate the spread swine flu rather than focus on containment, a survey suggests.

The WHO said containment "is no longer a feasible option" on Monday, and did not recommend closing borders or restricting travel.

Experts on the global movement of flu say the WHO, U.S. Homeland Security Secretary Janet Napolitano and President Barack Obama are correct in not closing the border between the United States and Mexico, the epicenter of the outbreak, The New York Times reported Thursday. Experts told the Times that closing borders not only would not stop the spread of the virus, but also cause an economic collapse and possibly lead to more deaths.

Countries in Europe, Asia and South America, anxious about the swine flu outbreak, have banned pork imports despite assurances that consuming pork is safe. Other countries are screening passengers exhibiting flu-like symptoms.

Obama defended the decision not to close the U.S.-Mexican border, saying it would be "akin to closing the barn door after the horse is out."

Mitigation relies on non-pharmaceutical measures, such as frequent hand-washing, wearing a mask, working from home, keeping sick people out of schools, offices or other large-crowd situations, closing large-crowd venues, even canceling sporting events, The Times said.

Closing borders is dangerous because many goods needed in a pandemic are made abroad, Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told the Times. Countermeasures manufactured beyond U.S. borders include most masks, gowns and gloves, electrical circuits for ventilators and portable communications gear, pharmaceutical drugs and the raw materials to make them.